Environmental test chambers are widely use for component and product testing including but not limited to temperature testing. As an example (and depending upon the particular application), electrical printed circuit boards are tested under extremes of temperature. It is not unusual to subject such boards to temperature excursions from -40.degree. C. to +125.degree. C. (about equal to -40.degree. F. to 260.degree. F.) and excursions down to -54.degree. C. are used for military applications. And rates of temperature change per minute may be in the 3.degree. C. to 20.degree. C. range.
Exposure to such temperature changes provides an accelerated test, dramatically shortening the time required to "prove" board designs and cull out boards which may fail prematurely. Such exposure is not unlike that which might be experienced by a high performance military aircraft flying from ground level to very high altitude in a matter of minutes.
One of the factors affecting cost of circuit board testing is the degree of manual board handling required to be used over the course of the test. In one arrangement shown in U.S. Pat. No. 4,683,424 (Cutright et al.) a circuit board test apparatus uses a relatively large number of baskets, each containing a number of circuit boards to be tested. Each basket, not unlike a file drawer in appearance, has an electrical connector on its end wall. All boards in the basket are electrically attached to this connector which, in turn, is connected to a connector on the cart by which all such baskets are carried. To test, the cart connector is plugged into a connector on a wall of the test chamber. In another arrangement, individual drawer-like baskets are placed into a chamber rack and plugged to a basket-dedicated connector on the rear chamber wall.
It is apparent from the foregoing that basket handling time can be very significant. And connection and disconnection to and from such wall connector(s) is difficult in that the connector insertion and withdrawal forces are substantial. Even though the cart has a manual latching arrangement, the overall configuration is somewhat cumbersome.
An improved system for testing electrical circuit boards which uses a movable carrier for supporting the boards in a "unitized" arrangement and which has a powered insertion/ extraction assembly for easily and automatically transporting the carrier in either of two directions would be an important advance in the art.